The draconians were a humanoid dragon-like race that lived hundreds of years ago. As a species, they worshipped Tiamat, the five-headed goddess of the evil dragons -- but they did it in an unusual way: the five tribes of draconians each worshipped one of Tiamat's five heads. The tribes did not get along with each other. Minor conflicts grew into religious wars, which turned into genocidal campaigns of extermination, which eventually wiped out the entire draconian race and converted their entire kingdom into the Grey Desert.
It's not clear what Tiamat thought of all this. Some scholars speculate that Tiamat's five heads actually had separate minds back then, and each was trying to achieve dominance over the rest. (Some scholars speculate that Tiamat's five heads have separate minds even now, but that they've learned to present an appearance of unity.) Other scholars believe that Tiamat has always had one mind, and was merely playing a sick joke on the draconian people.
What matters for our story is that the draconians' magic was real, and some of it still exists today.